The objective of this research is to determine the feasibility of developing a new absorbable surgical mesh for pelvic floor reconstruction. The product is expected to reduce the incidences of erosion, extrusion, and infection that occur with synthetic non-absorbable mesh products, and be less expensive than allograft and xenograft prosthetics. The new device is expected to address a market of 200,000 pelvic prolapse procedures in the United States, and it is anticipated that this new product could help reduce the unacceptable number of women (currently 30%) requiring repeat prolapse surgery. The research approach will employ a new absorbable biomaterial, know as poly-4-hydroxybutyrate (also known as PHA4400), that has been show to have prolonged strength retention in vivo compared to existing absorbable suture biomaterials. The specific aims of the project are to: (1) prepare a batch of PHA4400 suitable for processing into PHA4400 yarn; (2) extrude PHA4400 into suitable yarn, and convert it into a knitted mesh suitable for use in pelvic floor reconstruction; (3) undertake an in vitro and in vivo assessment of the knitted mesh to determine its biocompatibility; and (4) demonstrate that the in vivo mechanical stability of a hernia repair with the PHA4400 knitted mesh at 3 months is at least comparable with an existing substitute used in pelvic floor reconstruction, and perform a morphological and histological study to assess tissue reaction and suitability of the PHA4400 mesh for use in pelvic floor reconstruction. In addition to developing a product that could improve surgical outcomes of pelvic prolapse procedures; the research will also help to introduce a new absorbable medical biomaterial into the medical community that could find other uses, for example, in controlled release, tissue engineering, and other medical devices.